The present invention is concerned with semiconductor manufacturing, and is more particularly concerned with apparatus for storing carriers in which semiconductor substrates are stored.
Semiconductor devices are made on substrates, such as silicon wafers or glass plates, for use in computers, monitors, and the like. These devices are made by a sequence of fabrication steps, such as thin film deposition, oxidation or nitration, etching, polishing, and thermal and lithographic processing. Although multiple steps may be performed in a single processing station, substrates must be transported between processing stations for at least some of the fabrication steps. Substrates are stored in open cassettes or sealed pods (hereinafter collectively referred to as xe2x80x9csubstrate carriersxe2x80x9d) for transfer between processing stations and other locations. Although substrate carriers may be carried manually between processing stations, the transfer of substrate carriers is typically automated. For example, a substrate carrier may be transported to a processing station in an automatic guided vehicle (AGV), and then loaded from the AGV onto a loading platform at the processing station by a robot. Another robot may extract a substrate from the substrate carrier and transport the substrate into a processing chamber at the processing station. When the fabrication steps are complete, the substrate is loaded back into the substrate carrier. Once all the substrates have been processed and returned to the substrate carrier, the substrate carrier is removed from the loading platform and transported to another location by the AGV.
Before or after extraction of substrates from the substrate carrier for processing, the substrate carrier may be stored on a storage shelf that is provided adjacent the processing station, or at a stocker unit that stores substrate carriers for a bay of processing stations. It is known to use a robot to place the substrate carrier on the storage shelf and to remove the substrate carrier from the storage shelf. Because automatic transport is employed, it is necessary that the storage shelf be very precisely aligned and positioned relative to the carrier transport robot and/or relative to other elements adjacent the processing station.
A loading and storage station installed adjacent to a processing station is disclosed in co-pending U.S. patent application Ser. No. 09/201,737 (AMAT No. 2862), entitled xe2x80x9cApparatus for Storing and Moving a Cassettexe2x80x9d. The ""737 patent application is incorporated herein by reference in its entirety.
The loading and storage station of the ""737 patent application includes a plurality of storage shelves so that a substrate carrier stocking capability is provided adjacent the processing station. The loading and storage station also includes a substrate carrier handling robot for moving substrate carriers between the shelves and a docking station. As noted before, the storage shelves must be precisely aligned and positioned relative to other elements of the loading and storage station. During conventional installation of the loading and storage station, a time-consuming and labor-intensive process is undertaken for proper installation and alignment of each of the storage shelves. It would be desirable to reduce the time and effort required for installation and alignment of substrate carrier storage shelves in connection with a loading and storage station or other substrate carrier stocking facility.
In accordance with a first aspect of the invention, a shelf module is provided that is adapted to store a plurality of substrate carriers. The shelf module includes (1) a plate; and (2) a plurality of shelves attached to the plate at respective elevations, each of the shelves being adapted to store a respective substrate carrier. Also provided are (1) an upper attachment mechanism adapted to attach an upper portion of the plate to a frame of a storage location; and (2) a lower attachment mechanism adapted to attach a lower portion of the plate to the frame of the storage location. At least one of the upper attachment mechanism and the lower attachment mechanism is adjustable so as to allow the plurality of shelves attached to the plate to be aligned to a reference as a unit.
In accordance with a second aspect of the invention, another shelf module is provided that is similar to the shelf module of the first aspect. However, in the shelf module of the second aspect, one of the upper and lower attachment mechanisms includes a gimbal joint and the other of the upper and lower attachment mechanisms is adapted to provided pitch and yaw adjustments to the plate. Numerous other aspects are provided, as are systems and methods.
Further features and advantages of the present invention will become more fully apparent from the following detailed description of exemplary embodiments of the invention, the appended claims and the accompanying drawings.